Voltage regulating device



Aug. 4, 1936. A. c. TURTLE VOLTAGE REGULATING DEVICE Filed Nov. 25, 19524 Sheets-Sheet 1 2, R mwfl m Ev T Z a mfi a an mm mm on x mm ww Aug. 4,1936. 2,049,635

A. c. TURTLE VOLTAGE REGULATING DEVICE Filed Nov. 25, 19:52 v

4 Sheets-Sheet 2 FIGJB FIGA;

INVENTOB A-CJ'U RTLE AI TORNEY Aug. 4, 1936. A, TURTLE 2,049,635

'VOL'IAGE REGULATING DEVICE Filed Nov. 25, 1952 4 Sheets-Shet s INVENTORA.C.TURTLE I Y .EWFmm [Z ATTORNEY Aug. 4, 1936. c. TURTLE I 2,049,635voLTRGE REGULATING DEVICE Filed Ndv. 23, 1952 4 Sheets-Sheet 4 139 1B511 i E4 117 n m l IN ENT O R A.O.TURTLE F1614 BY a ATTORNEY PatentedAug. 4, 1936 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to lamp circuit potential regulating means forcar lighting systems. It comprises a specially wound transformer havingits secondary winding connected to the terminals of a lamp circuit andits primary winding divided into at least two coils connected inparallel to a source of direct current through a special circuit makingand breaking mechanism which functions, in response to a change inpotential at the terminals of the direct current source, to effect acompensating change in the timing of the current impulses in one coilwith respect to those in the other coil so that the output voltage ofthe transformer is thereby maintained at an approximately constantvalue.

In its preferred embodiment the circuit making and breaking mechanismcomprises an interrupter in series with each primary coil, eachinterrupter embodying stationary and rotary contacts, the latter beingdriven by a suitable D. C. motor connected to the direct current sourceso that the speed of the motor varies in response to potential changesoccurring at the terminals of said source, and means including agovernor for automatically varying the angular displacement of therotary element of one interrupter with respect to the correspondingrotary element of the companion interrupter in response to changes inthe speed of the motor.

One particular advantage of this improved regulating means is that iteliminates the exces sive resistance losses introduced in the lightingsystem by the regulators heretofore employed for the same purpose.Another advantage is that it maintains the potential of the lightingcircuit when the potential at the primary source is abnormally low,whereas the regulators heretofore used are efiective only when thepotential at the primary source rises above its normal value.

Proceeding now to a more detailed description of the invention,reference will be had to the accompanying drawings, wherein Fig. 1 is atop plan view of a motor driven interrupter assembly adapted to be usedin accordance with this invention for automatically varying the phaserelation of the primary coils of the transformer.

Fig. 2 is a side elevation of the assembly appearing in Fig. 1.

Fig. 3 is an end elevation of said assembly.

Fig. 4 is a transverse sectional view showing the relative arrangementand mounting of the stationary and rotary contacts of the adjustableinterrupter, said view being taken substantially along the line 4-4 ofFig. 2 and certain parts that would otherwise appear being omitted forthe sake of clearness.

Fig. 5 is a view in longitudinal section of the rotary elements of theinterrupter appearing in 5 Fig. 4.

Fig. 6 is a view in elevation of a fitting employed for connecting therotary elements of the adjustable interrupter to a governor whichdetermines the angular displacement of said ele- 10 ments.

Fig. 7 is a view in longitudinal section of the rotary element of theremaining or non-adjustable interrupter.

Fig. 8 is a transverse sectional view along the 15 line 8-8 of Fig. 7.

Fig. 9 is a detail perspective view illustrating the construction andmounting of a special switch employed in accordance with this invention.

Fig. 10 is a wiring diagram of a lighting system embodying saidinvention.

Fig. 11 is a perspective view of a brush and brush housing assemblyprovided in accordance with this invention.

Fig. 12 is a sectional view taken along the line I 2-42 of Fig. 2.

Fig. 13 is a bottom plan view of a modified interrupter assemblyequipped with a spark quenching device.

Fig. 14 is a side elevation of the assembly appearing in Fig. 13.

Referring more particularly to the drawings, ll designates a shaftmounted in suitable bearing brackets l2 carried by a base I3. This shaftcarries the rotary contact elements of the interrupters generallyindicated at A and B and is driven by a suitable shunt wound directcurrent motor I 4 of the over-saturated field type, whose operatingspeed varies according to variations in the potential of the energizingcurrent supplied thereto.

The rotary contact assembly of the interrupter Av is shown in detail inFig, 5. It comprises a sleeve 15 having an axial bore l6 through whichthe shaft ll extends. Said sleeve is fitted with a pin I! which works inthe spiral shaft slot l8 (see Fig. 1) so that as the sleeve is movedalong the length of the shaft it is also turned to vary the angulardisplacement of the diametrically opposed contacts IS, carried at theouter surface of the sleeve, with respect to the angular displacement ofthe corresponding contacts 65 of interrupter B. These contacts l9comprise segments of conducting material fitted (see Fig. 4) 55 betweensegments 20 of insulating material, said segments being clamped to theouter surface of the sleeve between a shoulder 2| and a clamping nut 22,the inner faces of the shoulder and clamping nut being inclined as at 23to overlie the mitred ends 24 of the segments whereby the latter aresecurely held against radial displacement during high speed rotation ofthe sleeve i5. One end of the sleeve l projects beyond the nut 22 andcarries a disc 25 in threaded engagement therewith. The other end of thesleeve projects beyond the shoulder 2i and is rotatably connected to theaxially movable end member 26 of the governor generally indicated at 21in Fig. 1. As shown to advantage in Figs. 5 and 6, said member 26comprises two halves designated 26a and 261) which embrace the end ofthe sleeve [5 projecting beyond the shoulder 2i and are fastenedtogether by bolts 28 which engage in an outwardly facing annular groove29 formed in the sleeve so that the latter is held against axialmovement relative to the member 26 but is capable of independent rotarymovement.

The two halves of the axially movable governor member 26 are connectedby lugs 33 and pivots 3! to corresponding ends of a pair of links 32.The remaining ends of the links 32 are connected by pivots 33 to similarlinks 34 which, in turn, are connected by lugs 35 and pivots 36 to theremaining end member 3! of the governor, said member Bl being adjustabiyfixed to the shaft I i by the clamping nuts 38 so that the position ofthis member may be adjusted to regulate the tension of the governorspring 39. From this description it will be apparent that variations inthe speed of the motor M and the shaft 1 i in response to changes in thepotential of the current supplied to the motor results in the sleeve i5being moved axially of the shaft in one direction or the other, in thecourse of which the sleeve is turned about the shaft by means of the pinI? and the groove !8 to change the angular displacement of the contactsl9.

During rotation of the shaft I I the rotary contacts l9 engagesuccessively with four stationary contact brushes 4!, Ma, 4!?) and Hemade of carbon or other suit-able conductive material. Each brush isslidably mounted in a suitable housing 42 and is pressed inwardly by a.spring 43. The several housings 42 are carried between a pair ofsupporting plates 44 made of any suitable insulating material, saidplates having extensions t5 which, together with an interposed spacer45, are fastened as at M to an upright 4-8 carried by upper and lowerrods 49 mounted in the bearing brackets 52. The housings 42 may be ofany suitable construction. As here shown, each housing comprises fourmetal walls (42a, 42b, 42c and 62d) defining a rectangular guideway 426in which the brush works, said guideway being open at the inner end ofthe housing and being closed at the opposite end by a suitable coverplate 42f, the spring 43 being interposed between the cover plate 421and the outer end of the brush 4 Each brush housing is equipped with aterminal 50 passing therethrough and through suitable apertures in thehousing supporting plates 44.

An upright 52 similar to the upright 48 is carried by the previouslymentioned rods 48 and serves as a mounting for a switch generallyindicated at 53 (see Figs. 1 and 9). The movable contact 54 of thisswitch is provided with bearings 55 rotatably mounted on the bightportion 56 of a U-shaped bolt. The arms 51 of this bolt pass throughsuitable openings in the upright 52 and are clamped in place by means ofthe clamping shoulders and the clamping nuts 59. The movable contact 54is formed to present plate-like portions 54a and 55b. A spring 60arranged as shown in Fig. 9 tends to swing the plate portion 54a ofcontact 54 into engagement with a pair of stationary contact terminals5! and 62 also carried by the upright 52. The plate portion 54b ofcontact 54 is equipped with a. terminal 540 and carries a projectingmember 5411 made of insulating material. When the various parts arepositioned as shown in Fig. l the disc '35 engages the insulating member5M carried by the movable switch contact 54 and serves to hold the plateportion 5M oi this contact out of engagement with the stationary contactterminals 6! and 52. A particular purpose of this switch will beexplained hereinafter.

The movable contact assembly of interrupter B is shown in Figs. '7, 8and 12. It comprises a metal sleeve 56 carrying at its outer surface apair of diametrically opposed conducting segments 65 fitted betweenalternating segments 66 of insulating material, said segments beingclamped in place between the shoulder 61 and the clamping nut 53, theends of the segments being mitred as at 69 to fit the inclined inneredges i of the shoulders 61 and the nut 68. Sleeve 54 is fixed to rotatewith the shaft II by means of the set screw H. The rotary contacts 65 ofinterrupter B co-operate with four brushes 12, 12a, 12b and 520 whichare mounted exactly the same manner as brushes 4!, lla, ii?) and Meexcept that in the case of interrupter B the extensions 45 of theinsulating plates 4 between which the brush housings are mounted arefastened to the upright 52.

In describing the operation of the foregoing construction reference willbe had to the wiring diagram appearing in Fig. 10. In this figure 80designates a single core transformer having its secondary winding 8!connected to the terminals 82 of a lamp circuit 83. The primary of thetransformer is divided into two coils 84 and 85 each having one terminalconnected by conductor 86 and switch 8'! to the negative terminal B8 ofa direct current source such as a storage battery 89. The remaining endof coil 84 is connected by conductors 89 to the brushes 4| and ilo ofinterrupter A. The remaining brushes Mb and Me of this interrupter areconnected by conductors 9i and S2 with the stationary contact E! of theautomatic switch 53.

The remaining end of coil 85 is connected by conductors 93 to thebrushes i2 and 12a of in terrupter B. The two remaining brushes 12b andl'Zc of interrupter B are connected by conductors 94 and 92 to theaforesaid stationary contact 6! of the switch 53.

The positive terminal 88a of the battery 89 is connected through switch81 and conductors 95 and 95 to the terminals 540 carried by the movablecontact 54 of the switch 53. Conductor 95 also connects the positiveterminal of the battery to one terminal of the armature start ingresistance 91 and the shunt field 91a of the motor. The remainingterminal of the starting resistance 96 is connected to the positiveterminal 98 of the motor M by a conductor 99 which is also connected bya branch conductor l8!) to the stationary terminal 52 of the automaticswitch 53. The negative terminals HH of the motor !4 and the negativeterminal of the shunt field 91a are connected through conductors I02 and86 and switch 81 to the negative side of the battery 89. When the motorI4 is at rest the movable contact 54 of switch 53 is held in openposition by engagement with the disc 25 as shown to advantage in Fig. 1.With the parts in this position closure of switch 81 causes current toflow from the positive to the negative side of the battery via theconductor 95, the motor starting resistance 91, the motor terminals 98and MI, the shunt field 91a and the conductors I02 and 86. As the motorattains its normal operating speed the governor 21 acts to move thesleeve I5 and the disc 25 to the left until the movable contact 54 ofthe switch 53 is free to move into engagement with the stationarycontacts 6| and 62 under the influence of the spring 60 thereby closingthe automatic switch 53. This closure of switch 53 serves to cut out themotor starting resistance 91 and to cut in the interrupters A and B andthe primary coils 04 and 85. With the switch 53 in closed position theflow of current from the positive side of the battery to the motorterminal 98 is via the conductors 95 and 96, switch contacts 54 and 62and conductors I00 and 99 thus bypassing the starting resistance 91included in the original circuit. Current also flows in the closedposition of switch 53 via conductors 95 and 96, switch contacts 54, 62and 6| and conductors 9|, 92 and 54 to the brushes 4| b and 4Ic ofinterrupter A and the brushes 12b and 120 of interrupter B, and thencevia the co-operating rotary contacts of the interrupters and the coils84 and to the negative side of the battery.

The sliding and rotary movement imparted to the sleeve I5 of theinterrupter A by the governor 21 as the motor I4 attains its normaloperating speed fixes the normal angular displacement of the rotarycontacts I9 with respect to the rotary contracts 65. If there is anychange of potential at the battery terminals this immediately produces achange in the operating speed of the motor I4. The governor 21 thereuponacts to effect a certain further angular displacement of the sleeve I5and contacts I9 of interrupter A which results in a change in the timingof the impulses produced in coil 84 with respect to those produced incoil 85 that compensates for the change in the potential of the currentsupplied to said coils and maintains the output potential of thesecondary III at an approximately constant value. In other words, thechanges which are made in the angular displacement of the contacts I9 ofinterrupter A in response to potential variations at the batteryterminals serves to advance'or retard the interruptions of the primarycircuit including the coil 84 with respect to the interruptions of theparallel primary circuit including the coil 85 so that the effectiveflux producing ampere turns of the two primary coils remainsapproximately constant. In this connection it will be understood thatthe increased or decreased frequency of the interruptions due to changesin the operating speed of the motor I4 are compensated for by anaccompanying shortening or lengthening of the duration of the contactperiods of the interrupters so that the average voltage in the secondaryof the transformer will be maintained approximately constantirrespective of changes in the speed of the operating motor due tochanges of potential current at the terminals of the direct currentsource.

In order to prevent arcing at the interrupter contacts, condensers I05and I06 may be provided as indicated in Fig. 10. As here shown,condenser I05 is connected across the brushes 4| and 4Ib of theinterrupter A while the remaining condenser I06 is connected across thebrushes I2 and 12b of the interrupter B.

Reference characters I01 and I08, in Fig. 10, designate a pair ofrectifying units shunted across the leads to the primary windings of thetransformer to prevent arcing at the interrupter contacts due to theinductive effect of the primary coils. These rectifying units have theiroutput terminals connected to the leads and 93 and their input terminalsconnected to the lead 86 and are constructed in a well known manner sothat, when thus connected, they will offer a high resistance to the flowof current therethrough from the leads 90 and 93 while offeringrelatively low resistance to the flow of current therethrough in theopposite direction from the primary coils when the latter, due to theirinductive effect and to the opening of the primary circuit at theinterrupters, are acting as sources of energy that would tend to producearcing at the interrupter contacts in the absence of the valve action orshort circuiting eifect of the rectifiers. A choke coil may be used inconnection with the rectifying units as indicated at I09 in order toprevent a too rapid decrease in transformer current.

In Figs. 13 and 14 I have shown a slight modification illustrating themanner in which each interrupter may be equipped with a spark quenchingdevice for reducing arcing at the main interrupter contacts. Theinterrupter shown in these figures comprises two brushes I I I and II Iaco-operating with the rotary contacts which are the same as described inconnection with the previous figures. In this case, how-- ever, themetal sleeve C which carries the rotary interrupter contacts D has oneend extended beyond the adjacent brush support 44 and equipped with ametal cam H2 which is electrically connected to the sleeve and serves asa supplementary rotary contact element. This cam H2 has two cam liftsdesignated I I3 and H4. The cam lift H3 co-operates with a series ofmetal washers I I5 carried by a lever arm H6. One end of lever arm H6 ispivoted, as at I I1, and is electrically connected to the brush III, asindicated at H8. The other end of the lever arm H6 is apertured for thepassage of a screw II 9 and is confined between the screw carriedsprings I20 and I2I, the tension of which may be regulated by theadjusting nuts I22 and I23. The remaining lift H4 of cam H2 co-operateswith a series of washers I24 carried by a lever I25. This lever I25 hasits pivoted end I26 electrically connected to the brush HIa as indicatedat I2! and its opposite end confined between the springs I 28 and I29carried by a screw member I30 corresponding tothe previously mentionedscrew member I I9.

From the foregoing description it will be understood that thc washers H5and I24 constitute supplementary contacts in parallel with the brushesIII and IIIa which are periodically bridged by the cam II 2 whose camlifts H3 and I I4 are arranged so that the angular displacement of theirpoints H3a and I I4a is different from that of the main rotaryinterrupter contacts D. Due to this arrangement it will be seen thatwhen the main interrupter contacts D pass out of engagement with thebrushes III and HIa practically no arcing occurs since the primarycircuit, including the brushes III and IIIa, is still maintained byreason of the fact that the washers H5 and I24 which are in parallelwith these brushes are connected together by the cam II2. As viewed inFig. 14 the cam rotates in a clockwise direction and the primary circuitis broken when the points I I3a and I Ma of the cam pass out ofengagement with the washers I I5 and I24. The springs associated withthe free ends of the lever arms H6 and I25 serve to yieldingly maintainthe washers H5 and I24 in a position to co-operate with the cam lifts asherein described.

Having thus described my invention, what I claim is:

1. The combination of a transformer having two primary coils connected,in parallel, to a source of direct current and means for changing thetiming of the impulses produced in one coil wgh respect to thoseproduced in the other coil to compensate for changes in the potential ofthe current supplied thereto.

2. The combination of a transformer having two primary coils connected,in parallel, to a source of direct current and means acting in responseto potential changes at the terminals of said source for efiecting acompensating change in the timing of the impulses produced in one coilwith respect to those produced in the other coil so that the outputvoltage of the transformer is maintained approximately constant.

3. The combination of a transformer having two primary coils connected,in parallel, to a source of direct current, an interrupter in serieswith each coil, and means for varying the relative timing of saidinterrupters in response to changes in the potential supplied to saidcoils.

4. The combination of a transformer having two primary windings and asecondary winding on a common core, a source of direct current to whichthe primary windings are connected in parallel, an interrupter in serieswith each primary winding, and means, responsive to potential variationsat said source, for changing the relative timing of the interrupters sothat the output potential of the transformer is maintained approximatelyconstant.

5. The combination of a transformer having two primary windings and asecondary winding on a common core, a source of direct current to whichthe primary windings are connected in parallel, an interrupter in serieswith each pri-- mary winding, a motor for operating said interruptersconnected in circuit with said source so that the speed of the motor isdetermined by the potential at said source and varies therewith and agovernor functioning to automatically vary the timing of one of saidinterrupters with respect to the timing of the companion interrupterwhen the speed of the motor varies in response to potential variationsat said source.

6. Means for supplying a lamp circuit with alternating current ofapproximately constant potential from a primary source of variablepotential comprising a transformer having a secondary winding and twoprimary windings on a common core, the secondary winding being includedin said circuit, a source of direct current to which the primarywindings are connected in parallel, an interrupter in series with eachcoil and means for varying the relative timing of said interrupters inresponse to potential variations at said source.

7. The combination with a source of direct current of a transformerhaving two primary windings connected in parallel to said source andmeans for producing impulses in said coils including means for variablytiming the impulses produced in one coil with respect to those pro- 5duced in the other coil to regulate the output voltage of thetransformer.

8. The combination with a source of direct current of a transformerhaving two primary windings connected in parallel to said source, an 10interrupter in series with each coil and means for varying the timing ofone interrupter with respect to the timing of the other interrupter tocontrol the output voltage of the transformer.

9. The combination of a transformer having two primary coils connectedin parallel to a source of direct current, an interrupter in series witheach coil, means for varying the relative timing of said interrupters inresponse to changes in potential at the terminals of said source, andmeans connected across the terminals of each coil to prevent arcing atthe interrupter contacts due to the inductive effect of the coils whenthe primary circuits are broken at the interrupters.

10. The combination of a transformer having two primary coils connectedin parallel to a source of direct current, an interrupter in series witheach coil, a condenser connected in circuit with each interrupter toreduce arcing at the interrupter contacts and means for varying therelative timing of said interrupter in response to changes in potentialcurrent at the terminals of said source.

11. The combination with a source of direct current of a transformerhaving two primary windings connected in parallel to said source, aninterrupter in series with each primary winding, a motor for operatingsaid interrupters connected in circuit with said source so that thespeed of the motor is determined by the potential at the terminals ofsaid source, a governor functioning to automatically vary the timing ofone interrupter with respect to the other interrupter when the speed ofthe motor varies in response to potential variations at said source, anda switch mechanism functioning automatically to disconnect theinterrupters when the motor is at rest and to connect the interruptersin series with their respective primary windings when the motor hasattained a predetermined operating speed.

12. The combination with a source of direct current and a load circuitof a transformer having two primary windings connected in parallel tosaid source and a secondary winding connected to said load circuit, aninterrupter in series with each primary winding, a direct current motorfor operating said interrupters energized from said direct currentsource so that the speed of the motor varies in response to potentialvariation at said source, a governor functioning to automatically changethe timing of one interrupter with respect to the remaining interrupterwhen the speed of the motor varies, a switch arranged to automaticallyassume an open position when the motor is at rest so as to open circuitthe interrupters and the primary windings connected in series therewith,a starting resistance including in the motor circuit, means forautomatically closing said switch to include the interrupters andprimary windings in circuit with said source and means including saidswitch for bypassing said starting resistance when the switch is in itsclosed position.

13. The combination with a transformer and a source of direct currentincluded in the primary circuit of the transformer of interrupter meansfunctioning, in response to changes in the potential at said source, forefiecting a compensating change in the interruptions of said circuit sothat the output voltage of the transformer is thereby maintained at anapproximately constant value.

14. In a. system of electrical distribution the combination of a directcurrent source, a load circuit, means including an adjustableinterrupter for connecting said circuit to said source whereby analternating current is produced in said circuit, a direct current motorconnected to said source to operate at a speed proportionate to thevoltage across the terminals of said source and means actuated by saidmotor for adjusting the interrupter to maintain the voltage of the loadcircuit at a substantially constant value throughout a wide range ofvoltage variations at the terminals of said source.

ALFRED C. TURTLE.

